Is a plastic or metal water bottle better?
In many metal water bottles, stainless steel material accounts for the largest proportion. Stainless steel contains a lot of heavy metals, such as chromium content should account for more than 10%. Of course, stainless steel is a kind of metal with stable properties, but stability does not mean that it will not decompose harmful substances under any conditions, but is relatively stable. Different stainless steels have great differences. For example, some stainless steel water bottles on the market will turn black after a period of time, and some will be as bright and clean as new after a long time.
At present, the materials of plastic water bottle on the market mainly include PP, PC and tritan. Plastics do not contain heavy metals, PP is also a more stable one in plastics. However, the stability is also relative, and a small amount of organic matter will be precipitated under certain conditions. In the process of using all kinds of man-made organic materials, people have found all kinds of harmful substances to human body or environment. Therefore, PP materials can only be said to be relatively safe in the current cognitive range.
Due to people's pursuit of quality of life and health, the environmental requirements of plastic raw materials are also increasing. For example, when PC is hydrolyzed, BPA (bisphenol-A) is produced. According to modern medical research, BPA beyond a certain dose may affect human health (including animals). If a small amount of BPA is ingested for a long time, the endocrine system will be disordered, which is very likely to have adverse effects on the reproductive system and destroy the balance of sex ratio. Therefore, some countries and regions have restricted or banned PC. The Ministry of health and other departments issued a notice saying that bisphenol A was prohibited from being used in baby bottles since September 1, 2011. Facing the pressure of environmental protection, manufacturers are looking for materials that can replace PC. Eastman has developed a new generation of copolyester tritan.
Tritan has no BPA component in the polymerization process and does not release BPA during use.
Stainless steel, PP and tritan water bottles are relatively safe among the water bottles made of various artificial materials.